It is necessary to remove particulate matter and water from fuel being supplied to an engine in order for the engine to operate properly and to have a long service life. Accordingly, the fuel supply system for an engine will typically include a fuel filter apparatus for removing particulate matter from the fuel before it is supplied to the engine. Such filter apparatuses also sometimes include provisions for removing water from the fuel, pre-heating the fuel, and provisions for injecting anti-gel or lubricity additives. Such filter apparatuses may also include other devices such as thermostats, pressure sensors, or water sensors. The filter may also be required to perform additional functions to neutralize acids or oxidants in the fuel. In addition, a filter apparatus may be used for the lubrication system of an engine.
Such filters typically include a filter element for trapping the particulate matter in a media. The element is configured so that it can be removed and replaced periodically as it becomes plugged with particulate matter. In order to allow for removal and replacement of the element, it is often mounted inside of a filter housing, which is in turn attached to a filter base having an inlet and an outlet port adapted for attachment of fluid lines directing fluid in to and away from the filter apparatus.
It is desirable that the filter apparatus and element be constructed to facilitate servicing of the filter. It is also desirable that the element and apparatus be configured in such a manner that only the proper element can be inserted into the base and housing, to preclude errors during servicing. It is further desirable, particularly in filters used in dirty or dusty environments of the type encountered in earth moving and farm equipment, that the filter apparatus include features for precluding entry of dirt or dust into the system while the filter element is being replaced. Also, it is desirable to prevent the filter from being undesirably loosened or removed from the filter base.
It is also desirable that a filter apparatus include built-in features for facilitating replacement of the filter element, preferably without the need for tools, and that the filter apparatus provide a pleasing aesthetic appearance.
Previous filter apparatuses have been less than satisfactory in providing such needs, desired features and functionality. It is desirable, therefore, to provide an improved apparatus and method for filtering a fluid, and in particular for filtering fuel or lubricants supplied to an engine, in a manner that better fulfills one or more of the needs described above.